Hi,

next kernel panics when running fsfuzzer test on ext4 file system.

Machine Type: Power 7 PowerVM LPAR
kernel : 4.13.0-next-20170915
config : attached
Test: fsfuzzer

dmesg:
-----
EXT4-fs (loop1): couldn't mount RDWR because of unsupported optional
features (e4000000)
JBD2: no valid journal superblock found
EXT4-fs (loop1): error loading journal
EXT4-fs (loop1): mounted filesystem with ordered data mode. Opts: (null)
EXT4-fs error (device loop1): ext4_mb_generate_buddy:756: group 0, block
bitmap and bg descriptor inconsistent: 1077 vs 1045 free clusters
Unable to handle kernel paging request for data at address 0x00000008
Faulting instruction address: 0xd0000000084b0424
Oops: Kernel access of bad area, sig: 11 [#1]
BE SMP NR_CPUS=2048 NUMA pSeries
Dumping ftrace buffer: 
   (ftrace buffer empty)
Modules linked in: cramfs(E) dlci(E) 8021q(E) garp(E) mrp(E) af_key(E)
ieee802154_socket(E) ieee802154(E) rpcrdma(E) ib_isert(E)
iscsi_target_mod(E) ib_iser(E) libiscsi(E) ib_srpt(E) target_core_mod(E)
ib_srp(E) hidp(E) ib_ipoib(E) cmtp(E) kernelcapi(E) rdma_ucm(E)
ib_ucm(E) bnep(E) ib_uverbs(E) rfcomm(E) bluetooth(E) ib_umad(E)
rdma_cm(E) ecdh_generic(E) rfkill(E) ib_cm(E) iw_cm(E) pptp(E) gre(E)
l2tp_ppp(E) l2tp_netlink(E) l2tp_core(E) ip6_udp_tunnel(E) udp_tunnel(E)
pppoe(E) pppox(E) ppp_generic(E) slhc(E) crypto_user(E) ib_core(E)
nfnetlink(E) scsi_transport_iscsi(E) atm(E) sctp(E) dccp_ipv4(E)
netlink_diag(E) dccp_diag(E) ip6table_filter(E) af_packet_diag(E)
unix_diag(E) tcp_diag(E) udp_diag(E) ebtable_filter(E) bridge(E) sg(E)
ibmveth(E) rpadlpar_io(E) loop(E) xt_CHECKSUM(E) iptable_mangle(E)
 ipt_MASQUERADE(E) nf_nat_masquerade_ipv4(E) iptable_nat(E)
nf_nat_ipv4(E) nf_nat(E) nf_conntrack_ipv4(E) nf_defrag_ipv4(E)
xt_conntrack(E) nf_conntrack(E) ipt_REJECT(E) nf_reject_ipv4(E) tun(E)
stp(E) llc(E) rpaphp(E) kvm_pr(E) kvm(E) ebtables(E) ip6_tables(E)
dccp(E) inet_diag(E) iptable_filter(E) nfsd(E) auth_rpcgss(E) nfs_acl(E)
lockd(E) grace(E) sunrpc(E) binfmt_misc(E) ip_tables(E) ext4(E)
mbcache(E) jbd2(E) sd_mod(E) ibmvscsi(E) scsi_transport_srp(E) [last
unloaded: netlink_diag]
CPU: 15 PID: 32523 Comm: jbd2/loop1-8 Tainted: G        W   E
4.13.0-next-20170915-autotest #1
task: c000000189664900 task.stack: c0000009f122c000
NIP:  d0000000084b0424 LR: d0000000084a8040 CTR: c000000000373fe0
REGS: c0000009f122f590 TRAP: 0300   Tainted: G        W   E
(4.13.0-next-20170915-autotest)
MSR:  800000000280b032 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI>  CR: 28002022
XER: 20000000  
CFAR: c000000000008718 DAR: 0000000000000008 DSISR: 40000000 SOFTE: 1 
GPR00: d0000000084a8040 c0000009f122f810 d0000000084bf010
c00000093b66a7d0 
GPR04: f0000000024ed980 c00000093b66a578 c00000093b66a578
0000000000000001 
GPR08: 0000000000000000 0000000000000000 0000000000000000
d0000000084b2738 
GPR12: c000000000373fe0 c00000000e939d80 c000000000118350
c0000013f0bc22c0 
GPR16: c0000009f65e4000 c0000009f122fb20 0000000000000000
c00000108a749824 
GPR20: c0000009f791cf9c 0000000000000000 c0000009f791cf60
d0000000084b6cb0 
GPR24: 0000000000000000 c00000108a749880 0000000000000000
c0000009f791d300 
GPR28: c00000093b66a7d0 c0000009f122c000 0000000000000000
c0000013f8f389b8 
NIP [d0000000084b0424] .jbd2_journal_put_journal_head+0x94/0x22c [jbd2]
LR [d0000000084a8040] .__jbd2_journal_remove_checkpoint+0x70/0x200
[jbd2]
Call Trace:
[c0000009f122f810] [d0000000084b04ec] .jbd2_journal_put_journal_head
+0x15c/0x22c [jbd2] (unreliable)
[c0000009f122f890] [d0000000084a8040] .__jbd2_journal_remove_checkpoint
+0x70/0x200 [jbd2]
[c0000009f122f930] [d0000000084a8b98] .__jbd2_log_wait_for_space
+0x368/0x3d0 [jbd2]
[c0000009f122f9c0]
[d0000000084a8c5c] .__jbd2_journal_clean_checkpoint_list+0x5c/0xc0
[jbd2]
[c0000009f122fa60] [d0000000084a4e2c] .jbd2_journal_commit_transaction
+0x33c/0x2f80 [jbd2]
[c0000009f122fc90] [d0000000084ad160] .jbd2_journal_init_inode
+0x390/0x5a0 [jbd2]
[c0000009f122fd70] [c0000000001184ac] .kthread+0x15c/0x1a0
[c0000009f122fe30] [c00000000000b4e4] .ret_from_kernel_thread+0x58/0x74
Instruction dump:
7c2004ac 7d40f8a8 7d4a4878 7d40f9ad 40c2fff4 38210080 e8010010 ebc1fff0 
ebe1fff8 7c0803a6 4e800020 ebdf0040 <e93e000a> 79290fe0 0b090000
e93e0028 
---[ end trace bd674540a2bf235c ]---

Kernel panic - not syncing: Fatal exception

-- 
Regard's

Abdul Haleem
IBM Linux Technology Centre